By-pass switch



R. W. KELLY BY-PASS SWITCH Aug. 8, 1967 5 Sheets-Sheet 1 Filed Aug. 18, 1966 5 I @955 SCN M A WWW Z R. W. KELLY BY-PASS SWITCH Aug. 8, 1967 3 Sheets-Sheet 2 Filed Aug. 18, 1966 Robert 2% Kelly %w w W: tarwez R- W KELLY Aug; 8, 1967 BY-PASS SWITCH 3 Sheets-Sheet 3 Filed Aug. 18, 1966 S if A;

6171701227: Robert 2% Kelgf United States Patent 3,335,237 BY-PASS SWITCH Robert W. Kelly, Milwaukee, Wis., assignor to McGraw- Edison Company, Milwaukee, Wis., a corporation of Delaware Filed Aug. 18, 1966, Ser. No. 573,356 8 Claims. (Cl. 200-48) This invention relates to electric switches, and more particularly to an improved by-pass switch for use with such equipment as a voltage regulator.

When using a disconnect and bypass switch with a voltage regulator, it is desirable to be able to energize the controls of the regulator for test purposes by utilizing the switch to connect the regulator to the source, thereby avoiding the necessity of using other equipment to energize the regulator from a separate source. Although the desired result can be achieved through the use of three separate switches, such a system is undesirable in that it permits, through either inadvertence or inexperience, the opening and closing of the switches in the wrong sequence as well as affording the wanted operating flexibility. In the switch of the present invention, used to connect a regulator to a system, a first blade connecting the regulator to the load is interlocked with a by-pass blade such that opening of the first blade causes the by-pass to interconnect the source and load prior to interruption of the first blades connection to the load side of the regulator. A second switch blade connects the regulator to the source and may be selectively opened or closed independently of the first switch blade when such first switch blade is in an open position. An insulating member is disposed intermediate the first and second switch blades and serves to prevent opening of the second switch blade when the first switch blade is closed, and if the second switch blade is in an open position it engages the first switch blade to cause simultaneous closing of the first and second blades as the first blade is closed. The interlock between the first switch blade and the by-pass blade further opens the bypass as the first switch blade is closed, but only after both first and second switch blades are closed, and the regulator is connected to the system. Accordingly, the regulator is disconnected and the by-pass connection eifected by opening two switches, the regulator may be energized from the source at will by closing the second switch blade, and the regulator may be reconnected to the system through closing a single switch without having the load disconnected from the source at any time. The correct se quence cannot be avoided either through inadvertence or ignorance of proper procedure.

It is an object of this invention to provide an improved disconnect and by-pass switch for equipment such as voltage regulators.

It is also an object of this invention to provide a bypass switch for a voltage regulator wherein the source voltage may be applied to the unit for test purposes while the unit is disconnected from the load without the use of the other equipment.

It is a further object of this invention to provide a disconnect and by-pass switch with an interlock between the portions thereof to prevent improperly sequencing the opening or closing of the component switch elements.

These and other objects and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawings, wherein:

FIGURE 1 is a side elevation of a disconnect switch, including a by-pass switch, with certain portions shown in phantom view;

FIGURE 2 is a plan view of the switch of FIGURE 1;

FIGURE 3 is a view taken along line 33 of FIGURE 2 with one of the hook elements shown in phantom view;

ICE

FIGURE 4 is a side elevation of the disconnect switch of FIGURE 1 with the switch blade interconnecting the load circuit to the apparatus shown in the open position;

FIGURE 5 is a section view along line 5-5 of FIG- URE 1 showing the disconnect switch blades and porcelain member; and

FIGURE 6 is a schematic wiring diagram of the bypass switch connecting a regulator to a distribution system.

Referring to the drawings and particularly to FIGURE 1, a switch assembly is mounted on a pair of insulators 11, 12 which are, in turn, supported on a channel base member 13. Each of the insulators 11, 12 has a vertically spaced dual terminal assembly mounted thereon. Supporting the blade assemblies 15, 16 at the hinged ends thereof are a pair of terminal members 17, 18 respectively. A contact support 20 bolted to the insulator 12 has the terminal 18 secured thereto and also supports an insulator assembly 22 including a ceramic insulator member 23 which isolates the terminals 17 and 18 from one another. The terminal 17 is connected to the insulator assembly 22 by bolts 24 which project from the upper surface of the insulator 23 and extend through a spacer 25. At the latch end of each of the switch blade assemblies 15 and 16 a similar assembly mounts terminals 27 and 28 on the contact support 29 carried by the insulator 11, with the terminals electrically isolated from one another by the ceramic insulator 30. The blade assembly 15 is pivotally connected to the terminal 17 by a bolt 32, which extends through apertures in the blades 34 and pierce extruded openings in the terminal member 17, with intimate high pressure contact between switch blades and terminal maintained by spring washers 33 at either side of the blade assembly. In like manner the blade assembly 16 is pivotally connected to the terminal 18 by bolt 35 and spring washers 36.

The structure of the blade assemblies 15, 16 and the latch and pry-out devices, provided by the pull rings 37, 38 and latches 39, 40 are fully described in the co-pending application Ser. No. 319,432, filed Oct. 28, 1963, now Patent 3,248,510, issued Apr. 26, 1966, and assigned to the same assignee. Since the specific structural details of the switch blade assemblies form no part of the present invention, such will not be described in detail herein.

A by-pass blade assembly 42 is mounted on a terminal member 27 by a bolt 43 which passes through pierce-extruded openings in terminal member 27 and apertures in switch blades 44 with a nut 45, jam nut 46 and spring washers 47 cooperating to retain the blades in high pressure electrical contact with the terminal member 27. At one end, switch blades 44 are also aligned and spaced by a bolt 49 secured through the switch blade apertures with a spacing sleeve 50 extending between the blades. At the opposite end the switch blades 44 are spaced a greater distance apart to permit by-pass blades to swing upwardly without interfering with the blade assembly 15.

By-pass switch blades 44 have two pairs of horizon tally aligned apertures 52, 53 formed therein. A movable latch is carried by the by-pass blade assembly and includes a generally U-shaped locking element 55 which has the bight portion 56 thereof extending through apertures 52 and a latch bar 57 which extends through the blade apertures 53 and the apertured flattened end portions of the U-shaped locking element. A pair of tension springs 58, each respectively secured at the ends thereof to the latch bar 57 and the divergent end portions 59 of the bypass switch blades 44, serve to urge the movable latch toward the adjacent end of the by-pass switch blade assembly 42. A pair of rivets 60 extend through apertures in the vertically extending portion of the terminal member 27 and secure at one side thereof the latch retainer 61 and at the opposite side the blade stop 62. The blade stop 62 presents a pair generally triangularly-shaped flange portions 63 that project away from the terminal 27 to provide a camming surface and a blade stop or cooperating latch surface 65.

The switch blade assembly 15 has mounted at each outside surface of blades 34 a latch engaging, depending hook element 66 that projects from the lower edge of the assembly. The depending hooks engage the latch bar 57 intermediate the by-pass plates 44. When the switch blade assembly 15 is in the closed position, as shown in FIG- URES 1 through 3, the depending hooks confine the movable latch and retain the by-pass blade assembly 42. in the fully open position. As the switch blade assembly is pivoted clockwise, as seen in FIGURES 1 and 3, toward an open position out of contact with the terminal member 27, the depending hooks 66 through engagement with the latch bar 57 initiate a counter clockwise movement of the by-pass blade assembly 42 toward a closed position of engagement with the upwardly projecting contact, 68 mounted on the terminal member 28. Asthe by-pass blade assembly 42 pivots, the bight portion 56 of the U-shaped locking element 55 rides over the camming surface 64 of the blade stop 62 and the latch bar is released from engagement with the depending hooks 66, following sulficient rotation of the by-pass blade assembly 42 in a counterclockwise direction to permit the locking element bight portion 56 to be moved by the tension springs 58 into a position confronting the cooperating latch surface 65.,In this condition the driving connection between the by-pass blade assembly 42 and the blade assembly 15 has been terminated with the by-pass blade locked in the'bypass position until the locking element 55 has been positively moved against the force of the tension springs 58 to remove the same from abutting latching engagement with the blade stop 62. It will also be observed that as the blade assembly 15 is moved toward a disconnect position, out of electrical contact with the terminal 27, the by-pass blade assembly 42 is carried into electrical engagement with the contact 68 prior to interruption of electrical contact between the blade assembly 15 and the terminal member 27.

When the blade assembly 15 is pivoted from an open position, as illustrated in FIGURE 4, toward a closed position in the direction of arrow A of FIGURE 4, the lower longitudinally projecting portions 70 of the depending hooks 66 pivot pastthe latch bar 57'which then engages the camming surface 71 to move the locking element 55, against the biasing force of the tension springs 58, out of latching engagement with the blade stop 62. Thereafter contact between latch bar 57 and depending hooks 66 initiates pivotal movement of the by-pass bladeassembly 42 out of engagement with the contact 68 following rotation of the blade assembly 15 into a closed position with respect to the terminal member 27 with the latch bar 57 being confined by the depending hooks 66.

As seen in FIGURE 5, a bifurcated porcelain member 82 has an upper portion disposed between and secured to the switch blades 34 and a lower forked portion with projections that respectively are engageable with the transversely spaced blades of the blade assembly 16. ,The porcelainmember 82 serves to assure that the blade assemblies 15 and 16 are separated at all times and also provides an abutting driving engagement between such blade assemblies if the blade assembly 15 is closed while the blade assembly 16 is still in the open condition.

In operation, with the blade assemblies 15 and 16 in a closed position, the blade assembly 15 is opened which automatically closes the by-pass blade assembly 42 across the terminal members 68-and 27 to interconnect sources S and load L prior to disengagement between the blade assembly 15 and terminal member 27. Thereafter the blade assembly 16 may be selectively opened to wholly isolate the regulator from source S, or closed to energize the regulator the shunt coil and controls for testing. Referring to FIGURE 6, when both blade assemblies 15 and 16 are open and the by-pass 42 is closed the regulator is isolated from the system. When it is regulator, the switch blade 16 may be closed, whereupon the shunt coil 84, and consequently thercontrol circuit 85,

is energized while the series coils 86 remain out of the circuit. It is, accordingly, not necessary to provide another source for connection to and testing of the control circuit of the regulator. When it is desired to reconnect the regulator to the system, it is only necessary to close the switch connecting the regulator to the load L by pivoting the blade assembly 15 into full latching engagement with the terminal member 27. As the blade assembly 15 is pivoted in the direction of the arrow A in FIGURE 4 the porcelain member 82 engagesthe blade assembly 16, if the latter is in an open position out of contact with the terminal member 28, and simultaneously pivots the blade assemblies 15 and 16 respectively into contact with the terminal members 27 and 28. After both blade assemblies are in contacting relation with the terminals further pivoting of the blade assembly 15 de-latches the by-pass blade assembly 42 from the blade stop 62 and pivots the bypass blade assembly 42 to an open position. It is to be understood that the sequencing of the switch blade assemblies during both the opening and closing of the blade assembly occur during a single uninterrupted pivotal movement of the switch blade assembly 15.

While a specific embodiment of. the instant invention has been shown and described herein, it is to be understood that variations'may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A by-pass switch comprising first and second terminals; a first switch blade for selectively interconnecting said first and second terminals; third and fourth terminals; a second switch blade for selectively interconnecting said second, third and fourth terminals; athird switch element for selectively interconnecting said first and third terminals; first cooperating abutment means respectively carried by said first switch blade and said third switch element to cause said third switch element to interconnect said first and third terminals as said first switch blade is moved out of electrically interconnecting relation between said first and second terminals; second cooperating abutment means carried by said by-pass switch and interposed between said first switch blade and said second switch blade to cause said second switch blade to be in electrically interconnecting relation between said third and fourth terminals when said first switch blade is in contact with said first terminal, said second switch blade being independently selectively movable into and out of electrically interconnecting relation between said third and fourth'terminals when said first switch blade is in an open position out of electrically inter lzonnecting relation between said first and second ter mina s.

2. The by-pass switch of claim 1 wherein said first cooperating abutment means respectively carried by said first switch blade and said third switch element are engageable to move said third switch element into electrically interconnecting relation between said first and third terminals prior to the interruption of electrical contact between said first switch blade and said first terminal and to move said third switch element out of electrically interconnecting relation between said first and third terminals subsequent to re-establishment of electrical contact between said first switch blade and said first terminal as said first switch blade is moved from an open to a closed position.

3. The by-pass switch of claim 1 wherein said second cooperating abutment means comprises a body of in sulating material carried by said first blade and engageable with said second blade to form a driving connection therebetween to pivot said second blade into engagement with said third terminal as said first blade is pivoted into engagement with said first terminal.

4. The by-pass switch of claim l further comprising first latch means for retaining said first switch blade in contact with said first terminal and second latch means desired to test the for retaining said third switch element in closed contacting engagement with said third terminal, said first cooperating abutment means retaining said third switch ele ment in an open position when said first latch means retains said first blade in engagement with said first terminal and said second latch means retains said blade element in a closed position when said first blade is disengaged from said first terminal.

5. A by-pass switch comprising first and second terminals; first and second blade members selectively movable into and out of contact with said first and second terminals respectively; first interlock means carried by one of said blade members for preventing movement of said second blade member out of contact with said second terminal when said first blade member is in contact with said first terminal, said second blade member being independently movable into and out of contact with said second terminal when said first blade member is moved away from contact with said first terminal; a bypass blade movable into and out of a closed position electrically interconnecting said first and second terminals; second interlock means carried by said first blade member and engageable with said bypass blade to move said bypass blade into said closed position as said first blade is moved away from contact with said first terminal and to move said bypass blade out of said closed position as said first blade member is moved into contacting relation with said first terminal.

6. The bypass switch of claim 5 wherein said second interlock means engages and moves said bypass blade into said closed position before said first blade moves out of contact with said first terminal and said second interlock means engages and moves said bypass blade out of said closed position only after said first blade is in electrical contact with said first terminal.

7. The bypass switch of claim 5 wherein with said first blade member moved away from contact with said first terminal said second blade member may be moved from an open position to a position of engagement with said second terminal by engagement with said first interlock means as said first blade member is moved into contact with said first terminal whereby said first and second interlock means respectively function as said first blade member is moved into contact with said first terminal to move said second blade member into contact with said second terminal and to move said bypass blade to said open position.

8. The bypass switch of claim 5 wherein said bypass blade is pivotably mounted on said first terminal and pivotable into and out of contact with said second terminal.

References Cited UNITED STATES PATENTS 2,809,244 10/1957 Owens et al 20048 X 3,185,804 5/1965 Howell 20048 X 3,248,510 4/1966 McCloud 200-162 ROBERT K. SCI-IAEFER, Primary Examiner. H. HOHAUSER, Assistant Examiner. 

5. A BY-PASS SWITCH COMPRISING FIRST AND SECOND TERMINALS; FIRST AND SECOND BLADE MEMBERS SELECTIVELY MOVABLE INTO AND OUT OF CONTACT WITH SAID FIRST AND SECOND TERMINALS RESPECTIVELY; FIRST INTERLOCK MEANS CARRIED BY ONE OF SAID BLADE MEMBERS FOR PREVENTING MOVEMENT OF SAID SECOND BLADE MEMBER OUT OF CONTACT WITH SAID SECOND TERMINAL WHEN SAID FIRST BLADE MEMBER IS IN CONTACT WITH SAID FIRST TERMINAL, SAID SECOND BLADE MEMBER BEING INDEPENDENTLY MOVABLE INTO AND OUT OF CONTACT WITH SAID SECOND TERMINAL WHEN SAID FIRST BLADE MEMBER IS MOVED AWAY FROM CONTACT WITH SAID FIRST TERMINAL; A BYPASS BLADE MOVABLE INTO AND OUT OF A CLOSED POSITION ELECTRICALLY INTERCONNECTING SAID FIRST AND SECOND TERMINALS; SECOND INTERLOCK MEANS CARRIED BY SAID FIRST BLADE MEMB ER AND ENGAGEABLE WITH SAID BYPASS BLADE TO MOVE SAID BYPASS BLADE INTO SAID CLOSED POSITION AS SAID FIRST BLADE IS MOVED AWAY FROM CONTACT WITH SAID FIRST TERMINAL AND TO MOVE SAID BYPASS BLADE OUT OF SAID CLOSED POSITION AS SAID FIRST BLADE MEMBER IS MOVED INTO CONTACTING RELATION WITH SAID FIRST TERMINAL. 